A conventional car circuit adapter is, generally, a very simple structure comprising an electrically conductive terminal serving as anode and an electrically conductive terminal serving as cathode in order to electrically connect a car cigarette lighter so as to provide battery power.
But, the design of the conventional car circuit adapter is too dull to be attractable. And, the function of the conventional car circuit adapter is also too simple to satisfy a user. For example, the conventional car circuit adapter is unable to show an on/off status when the conventional connector is in electrical connection with the car cigarette lighter.